Joint rehabilitation device and method

ABSTRACT

A device for exercise rehabilitation and evaluation of a joint between bone elements of the hand, of the arm or of the leg of a user includes: a portable housing ( 1 ), and magnetically controllable resistance devices ( 10,11,13 ). A rotable output shaft ( 9 ) is directly connected to the controllable resistance devices. Controllers ( 18 ) control for controlling at least the supply of current to the controllable resistance devices. Tools ( 40, 41 ) mount on the output shaft ( 9 ) and are gripable by or attached to the user during the rotation of the output shaft ( 9 ). The tools ( 40, 41 ) are in direct connection with the rotable output shaft ( 9 ) extending out of the housing ( 1 ). Mechanical positioners ( 20, 21, 22 ) are adapted to user&#39;s morphology that enable positioning the joint at a pre-determined position (x,y,z) in a three dimensional reference system attached to the housing ( 1 ). Mechanical constraints ( 30,31 ) block at least one bone element of the hand, the arm, or the leg at the position (x, y, z) while at least one degree of freedom is given to the joint.

FIELD OF THE INVENTION

The present invention is related to a joint rehabilitation device permitting the evaluation of the joint of the leg or the arm such as the hand, the wrist, the foot, the ankle, the knee or the elbow.

The present invention is also related to a method for using such rehabilitation device as a telemedicine tool.

Finally, the present invention is related to a computer program for performing such method.

TECHNOLOGICAL BACKGROUND

Joints are essential components of the human skeleton that enable humans to perform plenty of actions that are essential for their survival and the quality of their life. Preventing joints from accelerated ageing or rehabilitating joint after injury, surgery or illness are then a key action in the field of human well-being.

Joint dysfunction may result from injury, trauma, illness or other causes and usually requires, among other therapies, some physical rehabilitation involving ranges of motion and strength exercises of the affected joint.

In addition, hand, wrist, foot, ankle, knee or elbow injuries are more common today than in past years with the wide spread use of computer devices such as keyboards and other devices involving repeated movements with strained arm and leg positioning.

The handling of patients with such pathologies requires the intervention of a practitioner that mainly exercises its skills in clinics or in medical private offices. As a consequence, patients must schedule and make visit to use rehabilitation device under practitioner supervision, to guarantee the quality and the security of rehabilitation exercise.

Moreover, rehabilitation devices are usually large, heavy, expansive and stationary which again forces patient to perform exercises in clinics or medical private offices.

Accordingly, there is a need, therefore, for a rehabilitation device that can be carried to and used at a patient's home or other convenient place, but preferably under the supervision of a practitioner.

U.S. Pat. No. 6,117,093 discloses a hand and wrist rehabilitation device based on the use of a magnetic fluid controllable resistance brake. The user has a set of tool elements by which he applies a torque to the brake, these elements providing a grip for user's hand. The user controls the resistance of the brake thanks to a knob placed at the front panel of the device. The magnetic fluid controllable resistance brake is housed in a small portable case that possesses a clamp to mount the device to the table. The device described in this document does not allow to properly control the path of the movement as recommended by the practitioner for ensuring a suited therapeutic effect. Indeed, the user can only control the resistance of brake but does not control the rotating speed of the brake which does not allow to use the device in isokinetic mode. Moreover, the device does not allow to program a predefined isotonic pattern.

Moreover, the tool elements described in this document only limits the movements of user's hand but they do not put any physical constraints on the movement of user's wrist and arm. As a consequence, the nature of the tools gripped by user's hand can not be uniquely associated to a defined coordinated movement of user's hand, wrist, elbow and arm such as pronation/supination, abduction/adduction or flexion/extension. Finally, the device described in this document does not allow keeping track of user's performances, letting user exercising on his own without any feedback to the practitioner.

U.S. Pat. No. 4,765,315 discloses a muscle exercise and rehabilitation device. This device includes a movable fixture against which a torque can be applied; a particle brake clutch that provides a brake action against the actuating force; a control circuit that modulates the supply of braking current thereby enabling the apparatus to work at least in an isokinetic, isometric or isotonic mode. The angular range of movement of the movable fixture and the operating mode—isokinetic, isometric and isotonic—are defined using a control box placed at the front panel of the device. The device described in this document does not allow an accurate and repeatable human joint location relatively to the output shaft. Moreover, the said device does not allow processing and storage of user's performances, and cannot be programmed.

Patent application WO2006/099484 describes a mechanical hardware used in various muscular rehabilitation and exercise devices designed for the gripping motion of the hand. All of the disclosed embodiments make use of electro-rheological fluid (ERF)-based actuators in order to generate controllable variable resistance acting against the user hand motion. The resistance can be tuned by changing the intensity of the high voltage electric field applied to the ERF. Depending on each specific embodiment, the actuator can either be a rotary brake or a linear damper. When a rotary brake was used, it had to be combined with a gearbox in order to achieve a high enough resistive torque/force while maintaining the device compact. Sensors are embedded in the device providing position, speed, acceleration and force measurements that are useful for the close-loop control of the various exercise modes. As the proposed devices only resist to the motion of the user, elastic material or springs are used in order to make the devices return in their starting position at the end of the exercise. Only non-magnetic materials have been used in the design of the devices in order to make them usable under high magnetic fields.

To date, no device fills in the following requirements: a portable device for rehabilitation that can be use in isokinetic, isometric, and isotonic mode; that can be easily configured by the user following practitioner advises; that offers tools to perform spatially defined paths of movement following practitioner advises and that allows a survey or an evaluation by the practitioner or the therapist. To date, no telemedicine tools achieves these requirements.

AIMS OF THE INVENTION

A first aim of the present invention is to provide a device and a method for rehabilitation exercises for the joints of the arm, of the leg or of the hand that do not have the drawbacks of the state of the art.

In particular, the present invention aims to provide a device and a method for rehabilitation that can be use without the permanence supervision of the practitioner.

Accordingly the device should be portable so that the patient can take it at home.

A further aim of the present invention is that it still permits the therapist or the practitioner to perform an evaluation of said exercises performed at home.

Therefore, the present invention aims to provide a device and a method for rehabilitation which offer a reproducibility of the measurement relating to the exercises performed by the patient. Said device and said method should of course be a device and a method which are particularly safe and can not be misused by the patient in particular when he is alone.

Another aim of the present invention is to provide a device and a method which allow the practitioner to evaluate the movement performed by the patient directly in real time if necessary.

PRINCIPAL FEATURE OF THE PRESENT INVENTION

The present invention is related to a devise and a method as well as a computer program as described in the claims.

As a first object, the present invention is related to a device for exercise rehabilitation and evaluation of a joint between bone elements of the hand, of the arm or of the leg of a user comprising at least:

-   -   a portable housing,     -   magnetically controllable resistance means,     -   a rotable output shaft directly connected to said controllable         resistance means,     -   control means for controlling at least the supply of current to         said controllable resistance means,     -   tool means mounted on said output shaft and being gripable by or         attached to the user while the rotation of the output shaft,         said tool means being in direct connection with the rotable         output shaft extending out of the housing,     -   mechanical positioning means adapted to user's morphology that         enable to position the joint at a pre-determined position         regarding a three dimensional reference system attached to the         housing,     -   mechanical constraint means for blocking at least one bone         element of the hand, the arm, or the leg at said position while         at least one degree of freedom is given to the joint.

In particular, said mechanical constraint means and said tool means collaborate to limit the number of degrees of freedom of the joint to at least one rotational degree of freedom and in particular to one rotational degree of freedom

Preferably, said mechanical constraint means are blocking three translation degrees of freedom of the joint at said position.

Preferably, said device further comprises:

-   -   precision sensing means for producing a signal corresponding to         the angular position of the output shaft,     -   precision sensing means for producing a velocity signal         corresponding to the angular velocity of the output shaft,     -   precision sensing means for producing of force signal         corresponding to the torque applied by the user on said output         shaft.

Preferably, said device further comprises control means for assigning the value of the resistance torque of the resistance means, the value of the rotation speed of the output shaft and/or the value of the resistance force.

Preferably, said controllable resistance means are controllable magneto-rheological (MR) fluid resistance means or controllable MR-fluid brake means.

Preferably, the control means have three operation modes being the isometric, isotonic and isokinetic modes.

Preferably, said (precision) mechanical positioning means achieve an accurate and repeatable human joint location relatively to the output shaft.

Preferably, the magnetically controllable resistance means are a magneto-rheological brake in the form of a stator delivering a controllable magnetic field and embedding a rotor with a gap there between and containing a magneto-rheological fluid, interconnected at its center with said output shaft supported by the stator.

Preferably, said output shaft bores a hole in its center, enabling to fill in the inner space of the rotor with the magneto-rheological fluid.

Preferably, the tool means are plugged in and/or removed from the rotable output shaft.

Preferably, the device further comprises

-   -   storage means for recording and storing said data,     -   a communication interface that is enable to communicate with an         external interface of the user or the practitioner.

Preferably, the housing with the controllable resistance means comprises adjustable clamping means for securely fixing the housing to a table or a support.

Preferably, said communication interface is connected to the external interface through an USB cable, Bluetooth or WIFI protocols or serial port interface.

Preferably, the external interface of the user is a hand-held electronic device comprising a processor, such as a personal digital assistant (PDA).

Preferably, the external interface of the practitioner is a computer.

As a second aspect, the present invention relates to a method of using the above mentioned device as a telemedicine tool which comprises the following steps of:

-   -   setting the parameters of the said device following practitioner         advises preferably through control means,     -   keeping track of the user's performances while using said         rehabilitation device,     -   analyzing the user's performances, preferably in real-time         conditions, or thanks to recorded data,     -   modifying the settings of the said parameters after analyzing         user's performances by the practitioner.

Preferably, the practitioner is able to remotely modify parameters of the control means through the external interface of the user programmed using the external interface of the practitioner.

Preferably, the user is able to connect a PDA or a computer directly to the control means or device using the communication interface to retrieve and record in real-time information acquired by data acquisition means.

Preferably, the user is able to connect a PDA or a computer directly to the control means or device using the communication interface to display visual feedback relative to user performances.

Preferably, the practitioner is able to connect a PDA or a computer directly to the external interface of the user in order to retrieve the parameters previously recorded by this external interface and to analyse the physical performances of the user.

Preferably, the practitioner is able to modify parameters of the control means or device in real-time using the external interface of the practitioner by the communication interface.

Preferably, the practitioner is able to connect a computer directly to the control means or device using the communication interface to retrieve in real-time information acquired by the data acquisition means.

Preferably, the practitioner is able to connect a computer directly to the control means or device using the communication interface, and to perform recording of the movement parameter and to analyze the physical performance of the user.

However, this method of using the computer should not be considered as a therapeutical method but as a telecommunication method wherein said rehabilitation device is used by the user and an analysing centre round the physical performance of the user analysed.

As a third aspect the invention is related to a computer program comprising a code able to execute the method described here above.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 displays a perspective view of a joint rehabilitation device according to the present invention.

FIG. 2 displays longitudinal section of the housing of the device along an axis perpendicular to the output shaft of the said device.

FIG. 3 displays a perspective view of mechanical positioning system.

FIG. 4 displays a perspective view of a joint rehabilitation device according to the present invention with a handle for performing flexion/extension exercises.

FIG. 5 displays a perspective view of a joint rehabilitation device according to the present invention with a handle for performing adduction/abduction exercises.

FIG. 6 displays perspective view of a joint rehabilitation device according to the present invention with a handle for performing pronation/supination exercises.

FIG. 7 displays a perspective view of a joint rehabilitation device according to the present invention with a handle for performing hands and fingers rehabilitation exercises.

FIG. 8 displays a front and a back view of a handle used for hand and fingers rehabilitation exercise.

FIG. 9 displays a front view of a handle used for flexion/extension exercises.

FIG. 10 displays a front and back view of a handle used for adduction/abduction exercises.

FIG. 11 displays a front and back view of a handle used for pronation/supination exercises.

FIG. 12 alternatively displays a perspective view of a joint rehabilitation device according to the present invention with a handle for performing adduction/abduction exercises.

FIG. 13 alternatively displays perspective view of a joint rehabilitation device according to the present invention with a handle for performing pronation/supination exercises.

FIG. 14 alternatively displays a perspective view of a joint rehabilitation device according to the present invention with a handle for performing hands and fingers rehabilitation exercises.

FIG. 15 alternatively displays a front and a back view of a handle used for hand and fingers rehabilitation exercise.

FIG. 16 alternatively displays a front view of a handle used for flexion/extension exercises.

FIG. 17 alternatively displays a front and back view of a handle used for adduction/abduction exercises.

FIG. 18 alternatively displays a front and back view of a handle used for pronation/supination exercises.

FIG. 19 displays a schematic view of the joint rehabilitation device components.

FIG. 20 displays a control scheme of the joint rehabilitation device.

DETAILED DESCRIPTION OF SEVERAL PREFERRED EMBODIMENTS OF THE PRESENT INVENTION

As in a first embodiment, the present invention is related to a device for exercise rehabilitation and evaluation of a joint of the arm or the leg comprising at least:

-   -   a portable hand-holdable housing (being of a size to facilitate         ease of hand carrying by a user thereof);     -   a controllable resistance means with a rotable output shaft         extending out of the housing,     -   tool means mounted to said output shaft being gripable by or         attached to the user during the rotation of the output shaft,     -   embedded control means for controlling the supply of current to         said resistance means,     -   precision sensing means for producing a signal corresponding to         the angular position of the output shaft,     -   precision sensing means for producing a velocity signal         corresponding to the angular velocity of the output shaft,     -   precision sensing means for producing a force signal         corresponding to the torque applied by the user on said output         shaft,     -   data acquisition means in order to acquire or record data being         the signals measured by the sensing means and,     -   high precision mechanical positioning means.

Preferably, the embedded control means have 3 operation modes being the isometric, isotonic or isokinetic modes.

Preferably, the controllable resistance means are magnetically controllable resistance means, such as controllable MR-fluid resistance means or controllable MR-fluid brake means.

Preferably, the magnetically controllable resistance means are a magneto-rheological brake in the form of a stator delivering a controllable magnetic field and embedding a rotor with a gap there between and containing a magneto-rheological fluid, interconnected at its center with said output shaft supported by the stator.

Alternatively, said output shaft bores a hole in its center, enabling to fill in the inner space of the rotor with the rheological fluid.

Preferably, the tool means are plugged in and/or removed from the rotable output shaft.

Preferably the device further comprises

-   -   storage means for record and store said data,     -   a communication interface that is able to communicate such data         with any type of external interface of the user or the         practitioner.

Preferably, said mechanical positioning means are adapted to user's morphology.

Preferably, said precision mechanical positioning means enables to achieve an accurate and repeatable human joint location relatively to the output shaft.

Preferably, said housing of the controllable resistance means comprise adjustable clamping means for securely fixing the device to a table or a support.

Preferably, said communication interface is connected to the external interface through an USB cable, Bluetooth or WIFI protocols or serial port interface.

Preferably, said external interface of the user can be any hand-held electronic device comprising a processor, such as a personal digital assistant (PDA).

Preferably, said external interface of the practitioner is any type of computer.

As a third aspect, the present invention is related to a computer program comprising a code able to execute the method described here above.

Preferably the present invention is intended to be used as a portable rehabilitation device that comprises a magneto-rheological fluid-based brake that operates in isotonic, isometric and isokinetic modes, a fixation plate, a mechanical position system and several handles; all these component being portable as a whole by the user from the practitioner office to a convenient place for the user, for example by using a regular case. Moreover, the said portable device comprises sensors and controllers electronics that enable to program and to tune the brake in order to operate in isotonic, isometric, and isokinetic modes and to perform acquisition of data related to user's performances.

The said portable device comprises (bio)mechanical constraint means.

The term ‘(bio)mechanical constraint means’ is intended to mean any means that are blocking the three translational degrees of freedom of the joint.

For example, the biomechanical constraint means comprise a lower arm attachment—fixed to the mechanical positioning system—that comprises hook-and-loop fasteners such as Velcro® strips and an elbow blocking part, so that no translational motion can be performed by the joint.

When gripping the tools means, the user has restrain his/her movement to a rotation following the axis of rotation defined by the output shaft. Therefore, the tools means preferably restrain the number of rotational degrees of freedom to one.

Consequently, the (bio)mechanical constraint means and the tools means collaborate to limit the number of degree of freedom of the joint to one rotational degree of freedom.

Said tools (handles) are directly connected to the output shaft of the said magneto-rheological fluid-based brake which means that the said tool means and the said output shaft rotate at the same rotational speed.

The said rotatable output shaft is directly connected to the controllable resistance means that are magnetically controllable resistance means which means that the said rotatable output shaft and the said magnetically controllable resistance means always rotate at the same rotational speed.

Indeed, a gear box is not required between the output shaft and the handles.

The magneto-rheological fluid (MR fluid) comprises a suspension of micrometer-sized magnetic particles in a carrier fluid.

Preferably, the MR fluid comprises additives that discourage gravitational setting and promote particles suspension.

Preferably, the MR fluid comprises 20-40 percent by volume of relatively pure, 3-10 micron diameter iron particles, suspended in a carrier liquid such as mineral oil, synthetic oil, water or glycol.

Preferably, the MR fluid exhibits dynamic yield strengths ranging from 50 to 100 kPA, when the applied magnetic field ranges from 150 to 250 kA/m.

Preferably, the MR fluid has an off-state viscosity ranging between 0.20 to 0.30 Pa-s at 25° C.

Preferably, the response time of the MR fluid is inferior to 10 ms.

Preferably, the current supplied to the brake falls within the range between 0 A and 2.5 A.

Preferably, the voltage supplied to the brake falls within the range between 0 V and 48 V.

Preferably, the magneto-rheological fluid-based brake (MR brake) is a radial brake.

Alternatively, the MR brake is an axial brake.

Here, the term ‘radial brake’ is intended to mean a brake characterised by a magnetic field perpendicular to its axis of rotation, with active fluid areas located at the external periphery of the rotor.

Here, the term ‘axial brake’ is intended to mean a brake characterized by a magnetic field parallel to its axis of rotation.

The present invention is used in combination with a hand-held computer for the user and a computer for the practitioner that both run specific software enabling the importation and the storage of acquired data from the rehabilitation device, the configuration of the latter following practitioner instruction, the access to the list of exercises to be performed by the user, the display of real-time performance to the user and/or to the practitioner.

Advantageously, the present invention by combining a MR-fluid brake directly connected to the output shaft—itself directly connected with the tool means—with positioning means, (bio)mechanical constraint means, precision sensing means and means for pre-determining the value of the torque resistance solves the drawbacks of prior art.

According to a preferred embodiment described in FIG. 1, the device comprises a housing (1) attached with two manual knobs (5) to a fixation plate (8); the latter possessing two clamps (6) that enables fixation to a table; and a mechanical positioning system (2) attached to the fixation plate (8) with two manual knobs (7). A handle (3) is connected—thanks to a fixation knob (4)—to an output shaft (9) extending from the housing (1). The output shaft (9) is connected to a controllable resistance device, described below, that provides selectable resistance to the rotation of the output shaft (9).

According to a preferred embodiment described in FIG. 2, the device comprises a magneto-rheological brake as the controllable resistance device that comprise a rotor (10) interconnected at its center with the output shaft (9) embedded in a stator (11); this two mechanical parts are in contact through a magneto-rheological fluid (13) (MR fluid) composed of micron-sized magnetic particles, located inside an insulating liquid carrier. The viscosity of the MR fluid depends on the magnetic field to which the MR fluid is exposed, the magnetic field being produced by a coil (12) wound on a spool embedded in the stator (11).

A section of the rotor (10) in a plane comprising the output shaft has a T-shaped profile.

The current supply to the coil (11) is controlled by a electronic control device (18) which is connected to two precision sensing device. The first one is a stress gauge or a force sensor (17) that produces a force signal corresponding to the torque applied by the user on the output shaft (9); whereas the second is an encoder (19) that produces two signals corresponding respectively to the angular position of the output shaft (9) and to the angular velocity of the output shaft (9). The electronic control device or unit (18) analyzes these signals and consequently adapts the current, and per se the resistance of the brake in accordance with the selected mode of operation; i.e. isometric, isotonic or isokinetic.

The rotor (10) and the stator (11) are embedded in a case (14). Washers (15) placed in sandwich between the case and the stator prevents any leakage of MR fluid. Ball bearings (16) support the output shaft (9) for rotation relative to the case.

A three dimensional reference system is attached to the housing of the shaft.

The position (x,y,z) of the joint relatively to the shaft in the three dimensional system is determined using the said mechanical positioning system.

According to a preferred embodiment described in FIG. 3, the device comprises the mechanical positioning system (2) is composed of six main elements: a lower plate (20), a middle plate (21), an upper plate (25), a millimeter graduated jack (29), a lower arm attachment (30) and an elbow blocking part (31). The lower plate (20) comprises two manual knobs (7) used to fix it to the fixation plate (8) and a linear guide (22) that linked the lower plate (20) with the middle plate (21). The position of the middle plate (21) along the X axis—defined as the axis running along the length of the lower plate (20)—is precisely adjustable using graduated gorges (24) equipped with a manual knob (23). The upper plate (25) is also linked with the middle plate (21) using a linear guide (26). In this case, the position of the upper plate (25) along the Y axis—defined as the axis perpendicular to the X axis within the plane of the upper plate (25)—is precisely adjustable using graduated gorges (27) equipped with a manual knob (28). The millimeter graduated jack (29) has its bottom plate connected to the upper plate (25); the position of the top plate of the millimeter graduated jack (29) is adjusted following the Z axis, defined as the axis perpendicular to the plane containing the axis X and Y. The lower arm attachment (30) and the elbow blocking part (31) are screwed onto the top plate of the millimeter graduated jack (29), the size of these two elements depends on user's morphology.

According to a preferred embodiment described in FIG. 3, the device comprises the mechanical positioning system (2) is composed of six main elements: a lower plate (20), a middle plate (21), an upper plate (25), a millimeter graduated jack (29), a lower arm attachment (30) and an elbow blocking part (31). The lower plate (20) comprises two manual knobs (7) used to fix it to the fixation plate (8) and a linear guide (22) that linked the lower plate (20) with the middle plate (21). The position of the middle plate (21) along the X axis—defined as the axis running along the length of the lower plate (20)—is precisely adjustable using graduated gorges (24) equipped with a manual knob (23). The upper plate (25) is also linked with the middle plate (21) using a linear guide (26). In this case, the position of the upper plate (25) along the Y axis—defined as the axis perpendicular to the X axis within the plane of the upper plate (25)—is precisely adjustable using graduated gorges (27) equipped with a manual knob (28). The millimeter graduated jack (29) has its bottom plate connected to the upper plate (25); the position of the top plate of the millimeter graduated jack (29) is adjusted following the Z axis, defined as the axis perpendicular to the plane containing the axis X and Y. The lower arm attachment (30) and the elbow blocking part (31) are screwed onto the top plate of the millimeter graduated jack (29), the size of these two elements depends on user's morphology. The definition of the axis corresponding to the axis along which the middle and the upper plates slide in this paragraph apply to all the type of exercise to be performed except for the pronation/supination exercises.

In the case of pronation/supination exercises as depicted in FIG. 6, the Y axis is defined as the axis running along the length of the lower plate (20) and the X axis is defined as the axis perpendicular to the Y axis within the plane of the upper plate (25).

The mechanical positioning system (2)—as described here above—can be fixed to the fixation plate (8) in several manner relatively to axis of the output shaft (9), depending on the type of exercise to be performed by the user.

In order to achieve a high reproducibility in the measurements, the said mechanical positioning system is used in combination with the device.

The resolution of position in the X, Y, Z directions is 1 mm.

This system is used to locate the wrist joint always in the same way relatively to the device output axis.

It should enable the device to achieve a coefficient of variance smaller or equal to 20% between two identical measurements whatever the value measured.

As shown in FIG. 4, in the case of flexion/extension exercises the mechanical positioning (9) system is attached to the fixation plate (8) such as the user's arm is perpendicular to the axis of the output shaft (9). In the case of adduction/abduction exercises, the mechanical positioning (9) system is attached to the fixation plate (8) such as the user's arm is perpendicular to the axis of the output shaft (9) as depicted in FIG. 5 and FIG. 12. Inversely, in the case of pronation/supination exercises, the mechanical positioning (9) system is attached to the fixation plate (8) such as the user's arm is parallel to the axis of the output shaft (9) as depicted in FIG. 6 and FIG. 13.

According to a preferred embodiment of the invention, the user applied a force to the output shaft (9) using a handle (3) that is grasped by the user. Depending on the type of exercise performed by the user several handle are available.

FIG. 8 and FIG. 15 displays a handle that is used for hand and fingers rehabilitation exercises and mainly composed of two handles (40,41) forming a pliers. The handle is fixed to the output shaft (9) with a fixation knob (4) whereas two small knob (42) allow to fix the handle to the housing (1).

The mechanical positioning device is not represented in FIG. 8 and FIG. 15, nevertheless, it is used when performing such exercises.

FIG. 9 and FIG. 16 displays a handle dedicated to flexion/extension exercises that is composed of narrow plate (45), a fixation knob (4)—screwed at the centre of this plate on one side—and a grip (44) that is fixed to the plate on the other side. The position of the grip (44) is adjusted using graduated gorges (43) hollowed in the plate. The handle is fixed to the output shaft (9) with the fixation knob (4).

FIG. 10 and FIG. 17 displays a handle that is used for adduction/abduction exercises and similar to the one used for flexion/extension exercises. The only difference concerns the fixation of the grip that is realised using an additional element with triangle shape (46) and that allows the grip to be perpendicular to the axis defined by the output shaft.

FIG. 11 and FIG. 18 displays a handle dedicated to pronation/supination exercises and that is composed of narrow plate, a fixation knob (4)—screwed at the centre of this plate on one side—and a U-shaped grip (47) that is fixed to the plate on the other sides. The position of the grip (47) is adjusted using graduated gorges (43) hollowed in the plate. The handle is fixed to the output shaft (9) with the fixation knob (4).

FIG. 19 displays a schematic view of three main device components and their internal components. Three components are the mechanical hardware, the user interface and the embedded electronics.

FIG. 20 displays the three overlapping control loops that are used to command the device. The first control loop is a current loop used to compensate for the electrical time delay related to the use of coils to generate the magnetic field inside the brake.

The second control loop is a torque loop used to compensate for the non-linearity between the current applied to the brake and its output torque, the hysteresis cycle and the remanent magnetic field.

The third control loop is a motion loop used to control the motion of the output shaft according to the selected exercise mode (isometric, isotonic, isokinetic) and type (pronation/supination, abduction/adduction, flexion/extension, hand, finger). The exercise controller is thus different for each exercise mode.

As far as the communication between the user interface (computer/PDA) and the device is concerned, the user interface is the MASTER device and the device, the SLAVE device. This means that all messages coming from the device microcontroller are an answer to a request from the user interface. The messages exchanged vary from one exercise mode to another. The protocol used to perform this communication is the SLIP protocol.

User's Cases

The method for using the device described hereabove will be described in further details in the following example of user's cases, which are not in any way intended to limit the scope of the invention as claimed.

The following examples are intended for illustration purposes only, and should not be considered as limiting the scope of the invention in any way.

The joint rehabilitation device can be used in several conditions either in the presence of an operator of the said device or in absence of an operator or in any place suitable for the user such as alone at home.

The first user scenario is the case when the device is connected to the operator's COMPUTER.

The first operation to be performed is to physically connect the device to the COMPUTER either trough physical means such as a USB or SERIAL interface or through wireless means such as a WIFI or Bluetooth interface. Then the operator must start the software and switch the device on. If for any reason, the device is not connected to the COMPUTER (and/or not powered on) when the software is started, the operator is first asked to connect the device to the COMPUTER (and/or to switch it on) before going further. He is also offered the possibility to use the software without the device but then he will not be able to start any exercise until the device is connected to the COMPUTER.

Once the device is powered on and connected to the COMPUTER, a pop-up window appears asking the operator to perform calibration of the sensors. No other operation can be performed until calibration is complete.

The operator is first asked to remove from the device any exercise handle that may still be connected to it.

The position sensor used in the device is an incremental encoder. It means that the position is measured relatively to a reference position that has to be identified each time the device is powered on. In order to calibrate the position sensor, the operator is asked to perform a complete revolution with the handle of the device. It enables the sensor to detect the index pulse. Knowing where this index pulse is located (from factory settings), the zero position can be retrieved. Alternatively, the operator can be asked to position the handle at a specific angle (by aligning visual markers located on both output axis and external housing). Once this is done, the operator clicks on a button allowing the software (and the device) to record this position as the reference position.

The signal provided by the force sensor may be shifted due to temperature; it has to be reset periodically. In order to calibrate the force sensor, the operator is asked to position the output axis in such a way that gravity can not have any influence on the measurement due to dissymmetry in the output axis (a visual marker can be used). The output axis is then left free and the operator specifies it to the software by clicking on a button. The measured force value at that moment is then considered by the device as the zero signal. Such a procedure has to be followed each time the device is powered on.

Such a procedure has to be followed each time the device is powered on.

Once the device has been calibrated, the operator can have an access to the user database managed by the software. He can either select an existing user or enter a new user in the database.

For a new user definition, the operator has to provide the following information to the software: first name, last name, ID number, birth date, height, weight, sex, preferred side, involved side. This data can also be edited and modified later on.

Once the user has been selected in the database, the operator can have access to the “exercise menu” where he can specify the exercises to be performed by the user and set the corresponding parameters. It is important to note that the operator is able to define exercises in advance for future exercise sessions.

Depending on the exercise mode selected by the operator, various parameters can be set. Some parameters are the same for all the exercise modes: date of the exercise, exercise type (flexion/extension, adduction/abduction, pronation/supination), number of trial repetitions, rest period duration after trial repetitions, number of effective repetitions, rest period after effective repetitions, tested side (involved/not involved), type of user interface used (COMPUTER or PDA) (in this case COMPUTER will be selected).

Other parameters differ from one exercise mode to another. For isometric exercise, the specific parameters are for example: the angle of measurement, the duration of measurement or the direction of measurement (agonist/antagonist). For isotonic exercise, the specific parameters are for example: the start angle (beginning of Range Of Movement—ROM), the stop angle (end of ROM), the torque profile for the agonist motion (constant, parabolic, . . . ), the torque profile for the antagonist motion (constant, parabolic, . . . ), the maximum torque value for the agonist motion or the maximum torque value for the antagonist motion. For isokinetic exercise, the specific parameters are for example: the start angle (beginning of ROM), the stop angle (end of ROM), the speed limit for the agonist motion (constant, parabolic, . . . ) or the speed limit for the antagonist motion (constant, parabolic, . . . ). If an exercise has not already been performed, the operator is still able to modify any of its parameters

According to the exercise to be performed first, the operator connects the appropriate handle to the output axis of the device using the manual knob. Then he fixes the user forearm to the lower arm attachment of the mechanical positioning system using hook-and-loop fasteners such as Velcro® strips while making sure that his elbow is properly blocked by the elbow blocking part.

It should be noticed that the lower arm attachment can have various standard sizes in order to fit to various morphologies.

Once the user has been properly attached to the positioning system, it is translated in the three directions (X,Y,Z) in order to position the axis of the wrist to be exercised in front of the output axis of the device. The location of the axis of the wrist to be exercised is identified by the operator using conventional palpation methods. Once the wrist of the user has been properly positioned, the X, Y, Z translations are blocked. If flexion/extension or adduction/abduction exercises are performed, the distance between the handle and the output axis is also fixed in order to fit to the dimensions of the hand of the user.

For each user, and for each exercise type (flexion/extension, adduction/abduction, pronation/supination) the operator can store in the database the mechanical settings used to position the wrist of the user in front of the axis of the device. These mechanical settings consist of the value of the positions in the three directions X, Y, Z (+position of the handle for the flexion/extension and adduction/abduction exercises).

This method enables the user to always position his wrist in the same way relatively to the output axis, for a given exercise, every time he uses the device. It is important to note that thanks to this positioning method the operator needs to perform a palpation of the wrist axes only once for each user and for each exercise type.

Once the user has been fixed in front of the output axis of the device, the exercise can be started. The operator has now access to the list of exercises previously defined and scheduled for the current day (exercises for future days are not displayed in order to avoid confusion). Exercises can be performed one at a time (which means that the sequence of exercises can be chosen by the operator) (“single set”) or all of them can be performed one after the other according to the sequence in which they have been defined (“all sets”).

Once an exercise has been selected, all the parameters relative to this exercise are sent to the embedded microcontroller of the device to make it ready to properly control the MR-brake according to the selected exercise.

In order to start the exercise, the operator has to click on the “start trial” button. The user then performs the trial repetitions. Data transmission from the embedded electronics is also started in order to provide real-time visual feedback—on the display of COMPUTER—to the user and operator. These repetitions are followed by a predefined rest period where data transmission is stopped. Once the rest period is over, the operator has to click on the “start exercise” button in order to launch the effective repetitions. Data transmission is again started and the user performs the effective repetitions. During the effective repetitions, transmitted data is also recorded in the user database for further analysis.

Once the effective repetitions are over, the operator clicks on the “finish” button to either end the exercise session or select/move to the next exercise.

The operator is also able to stop the exercise while it is being performed.

At the end of each repetition, the software informs the user on the repetition status (SUCCEEDED or FAILED) and if the repetition is failed, it tells the user why so he can take the corrective measures for the next repetitions. It should be noted that only the data from the succeeded repetitions will be used for further data computation.

When all the exercises have been performed, the user can remove his forearm from the device after unfastening the hook-and-loop fasteners such as Velcro® strips.

Once the exercise session is over (or even after each exercise), the operator can have access to extended computed data corresponding to the exercise that has been realised. In order to display this data, the operator must open the “user history” window where he can select the relevant exercise from a list of all the exercises previously performed by the user. The exercises of this list can be sorted according to any of the parameters used to define the exercises in order to facilitate data retrieval. It should also be noted that the operator has the possibility to delete an exercise from the list, in case he considers it as not relevant.

Once an exercise has been selected from the list, the operator can choose to either display the corresponding computed data or export them to spreadsheet program such as Excel®. If the selected exercise corresponds to an exercise conducted with the involved side, a comparison is automatically made with the performances achieved with the uninvolved (valid) side for the same exercise mode and type (if this data exists . . . ).

The software also offers the possibility to print a report containing all the displayed computed data and relevant information concerning the selected exercise.

When data analysis has been completed, the operator can select a new user (or create a new one) from the database and repeat the entire procedure. Alternatively, he can also switch off the device and close the software.

Alternatively, access to previous exercise results can also be done at any other time and can even be done without the device being connected to the COMPUTER.

Such a feature enables the operator to conduct further analysis and comparison of exercise results.

Alternatively, the joint rehabilitation device can be connected to a PDA.

When the device is used in combination with a PDA, the first operation to be performed by the operator is to select an existing user (or create a new user) in the user database managed by the software located on the operator COMPUTER.

For a new user definition, the procedure to be followed is identical to the one required when the device is used directly in combination with the COMPUTER.

Once the user has been selected in the database, the operator can have access to the “exercise” menu where he specifies the exercises to be performed by the user in the coming days. The way these exercises and their corresponding parameters are specified is nearly identical to the procedure followed when the device is used directly in combination with the COMPUTER. The only difference lies in the fact that, in the exercise definition, the parameter “type of interface used” is set to “PDA” instead of “COMPUTER”. The exercises that have been defined are then stored in the database managed by the software located on the COMPUTER.

For each different exercise type of the list of exercises previously defined, the operator checks (and stores in the database) the required mechanical settings for the user concerned using a procedure identical to the one followed when the device is used directly in combination with the COMPUTER. This has to be done only once for each user and for each exercise type. It can be done using a device located in the operator's practice, which is not especially the one that will be used by the user.

Once all the scheduled exercises have been defined and their parameters set, the operator has to load the exercises on the user PDA. This is done through the “PDA interface” window of the “exercise” menu. Various loading options are offered to the operator such as exercise loading with PDA connected to the operator COMPUTER (WIFI, Bluetooth, . . . ) (option 1), exercise loading through memory card (connected to the COMPUTER through a memory card reader) (option 2) or exercise loading through the Internet (option 3).

Whatever the loading option selected, a copy of the entries in the user database corresponding to all the scheduled exercises to be performed by the user alone (in the coming days) is sent to the PDA (either directly for option 1, or indirectly for option 2 and 3). The exercises are sent to the PDA in a specific file format such that they will be recognized by the exercise database located on the PDA.

For options 1 and 2, the exercise files are directly copied into the proper directory of the PDA memory card and will thus be directly incorporated into the exercise list. For option 2, this update of the exercise list will, of course, be effective only when the memory card will be inserted into the PDA.

For option 3, the exercise files are loaded and stored on a secured website that can be accessed by the PDA when the “load new exercises” button is pressed within the PDA software. This procedure requires that the PDA can be connected to the Internet (either through a GSM connection of through an external modem via WIFI or Bluetooth). Once the website has been accessed, the software automatically transfers the exercises files from the secured website to the proper directory of the PDA memory card and stops the connection at the end of the file transfer after having sent a message to the website specifying that the data has been properly transferred.

If the mechanical settings corresponding to the exercises to be loaded on the PDA have not been specified yet by the operator, the software located on the COMPUTER asks to the operator to specify them before loading the exercise files to the PDA. This data is also loaded on the PDA.

When the user is back home and wants to use the device, the first operation to be performed is to switch the PDA and the device on. The software commanding the device and managing the exercise database is automatically started. The first operation (automatically) performed by the software is to check whether the device is switched on or not and to check if the connection between the device and the PDA is properly working. If not, an error message is sent to the user.

Once the device is powered on and properly connected to the PDA, a pop-up window appears asking the user to perform calibration of the sensors. No other operation will be performed until calibration is complete. The calibration procedure is identical to the one to be followed when the device is used directly in combination with the COMPUTER.

Once the device has been calibrated, the PDA automatically presents to the user the exercise to be performed (which has been previously defined by the operator). At the same time, all the parameters relative to this exercise are sent to the embedded microcontroller of the device to make it ready to properly control the MR-brake according to the exercise to be performed.

Before starting the exercise, the PDA asks the user to check if the mechanical positioning system is in the proper position. For that purpose, the user has to check the current value of the X, Y, Z settings and compare them with the values provided by the PDA. The user also has to check if the mechanical positioning system is properly located relatively to the device and if the proper handle (with the proper setting) is connected to the output axis of the device. If any of these settings differ from the information given by the PDA, the user performs the required adjustments.

Once the mechanical positioning system and handles have been properly adjusted, the user fixes his involved forearm to the lower arm attachment of the mechanical positioning system using hook-and-loop fasteners such as Velcro® strips while making sure that his elbow is properly blocked by the elbow blocking part.

Finally the user informs the software that he is ready to perform the exercise by clicking on the “ready for exercise” button.

Once the user is ready to perform the exercise, he clicks on the “start trial” button. The user then performs the trial repetitions. Data transmission from the embedded electronics is also started in order to provide real-time visual feedback to the user via the PDA display. These repetitions are followed by a predefined rest period where data transmission is stopped. Once the rest period is over, the user has to click on the “start exercise” button in order to launch the effective repetitions. Data transmission is again started and the user performs the effective repetitions. During the effective repetitions, transmitted data is also temporarily recorded in the exercise database (located on the PDA) for later transmission to the operator's COMPUTER where further analysis will be performed.

Once the effective repetitions are over, the user clicks on the “finish” button to either move to the next exercise that will automatically be displayed by the PDA or end the exercise session if no more exercise is to be performed.

In case of emergency, the user is also able to stop the current exercise while it is being performed.

At the end of each repetition, the software on the PDA informs the user on the repetition status (SUCCEEDED or FAILED) and if the repetition is failed, it tells the user why so he can take the corrective measures for the next repetitions. It should be noted that only the data from the succeeded repetitions will be used for further data computation on the operator COMPUTER.

When all the exercises have been performed, the user can remove his forearm from the device after unfastening the hook-and-loop fasteners such as Velcro® strips.

Regularly (every day, every week . . . ), data acquired during previous exercise sessions and stored in the exercise database of the PDA is transmitted to the operator COMPUTER for further analysis. This data can be transmitted in various ways, similar to the ones used to load new exercises from the operator COMPUTER to the PDA such as through a USB cable, Bluetooth or WIFI protocols.

For data transmission with the PDA connected to the operator COMPUTER or through its memory card, exercise data stored on the PDA is directly transferred to the proper directory on the operator COMPUTER and will thus be directly incorporated in the list of exercises previously performed by the user that can be accessed by the operator through the “user history” window.

For data transmission through the Internet, a secured website is automatically accessed by the PDA at the end of each exercise session. Exercise data is then loaded and stored on this website until the operator connects his computer to the website and retrieves the exercise data by clicking on the “acquire exercise data” button from the “PDA interface” window after having selected the user concerned in the “user” menu. Once the website has been accessed, the software automatically transfers the exercise data from the secured website to the proper directory on the operator's COMPUTER and stops the connection at the end of the file transfer after having sent a message to the website specifying that the data has been properly transferred.

Once the exercise data has been transferred on the operator COMPUTER, the operator can have access to extended computed data corresponding to the exercises that have been performed at home by the user. In order to have access to this computed data, the operator has to select the relevant exercise from the list of all the exercises previously performed by the user (located in the “user history” window) in the same way as when the device is directly connected to his COMPUTER.

As described here above, depending on the user's cases the acquired data—such as position, speed, torque, time—can either be transmitted to the COMPUTER in real-time when the operator is directly connected to the machine through any I/O interface available or later on, by connecting the PDA—or directly its memory stick containing the acquired data—to the COMPUTER through any appropriate means.

Once the said data has been transmitted to the COMPUTER, it can be computed in order to provide to the operator information on the performances achieved by the user that can be compared to previously obtained data.

Whatever the user's scenario (exercising in front of the operator or alone at home), the acquired data (position/speed/torque/time) can either be transmitted to the computer in real-time when the operator's computer is directly connected to the device through a USB or serial connection or later on, by connecting the PDA (or directly its memory stick containing the acquired data) to the computer through any appropriate means.

Once this data has been transmitted to the computer, it can be computed in order to provide to the operator useful information on the performances achieved by the user that can be compared to previously obtained data. 

1. A device for exercise rehabilitation and evaluation of a joint between bone elements of the hand, of the arm or of the leg of a user comprising: a portable housing, means for magnetically controlling resistance, a rotatable output shaft directly connected to said means for controlling resistance, control means for controlling at least the supply of current to said means for controlling resistance, tool means mounted on said output shaft and being graspable by or attached to the user during rotation of the output shaft, said tool means being in direct connection with the rotatable output shaft extending out of the housing, mechanical positioning means adapted to a user's morphology that enables positioning the joint at a pre-determined position in a three dimensional reference system attached to the housing, mechanical constraint means for blocking at least one bone element of the hand, the arm, or the leg at said position while at least one degree of freedom is given to the joint.
 2. The device according to claim 1, wherein said mechanical constraint means and said tool means cooperate to limit the number of degrees of freedom of the joint to one rotational degree of freedom.
 3. The device according to claim 1, wherein said mechanical constraint means are blocking three translation degrees of freedom of the joint at said position.
 4. The device according to claim 1, further comprising: precision position sensing means for producing a signal corresponding to the angular position of the output shaft, precision sensing means for producing a velocity signal corresponding to the angular velocity of the output shaft, precision torque sensing means for producing of force signal corresponding to the torque applied by the user on said output shaft.
 5. The device according to claim 1, further comprising control means for assigning the value of the resistance torque of the resistance means, the value of the rotation speed of the output shaft and/or the value of the resistance force.
 6. The device according to claim 1, wherein said means for controlling resistance are controllable magneto-rheological (MR) fluid resistance means or controllable MR-fluid brake means.
 7. The device according to claim 1, wherein the control means have three operation modes being the isometric, isotonic and isokinetic modes.
 8. The device according to claim 1, wherein the magnetically controllable resistance means are a magneto-rheological brake in the form of a stator delivering a controllable magnetic field and embedding a rotor with a gap there between and containing a magneto-rheological fluid, interconnected at its center with said output shaft supported by the stator.
 9. The device according to claim 1, wherein said output shaft bores a hole in its center, enabling filling the inner space of the rotor with the magneto-rheological fluid.
 10. The device according to claim 1, wherein the tool means are plugged in and/or removed from the rotatable output shaft.
 11. The device according to claim 1, further comprising: storage means for recording and storing said data, a communication interface that enables communication with an external interface of the user or the practitioner.
 12. The device according to claim 1, wherein the housing with the means for controlling resistance comprises adjustable clamping means for securely fixing the housing to a table or a support.
 13. The device according to claim 1, wherein said communication interface is connected to the external interface through an USB cable, Bluetooth or WIFI protocols or serial port interface.
 14. The device according to claim 1, wherein the external interface of the user is a hand-held electronic device comprising a processor.
 15. The device according to claim 1, wherein the external interface of the practitioner is a computer.
 16. The method for using a device as claimed in claim 1 as a telemedicine tool, comprising the steps of: setting the parameters of the said device following practitioner recommendations through control means, keeping track of the user's performances while using said rehabilitation device, analyzing the user's performances, modifying the settings of the said parameters after analyzing the user's performances by the practitioner.
 17. The method according to claim 16, wherein parameters of the control means are remotely modifiable by the practitioner through the external interface of the user programmed using the external interface of the practitioner.
 18. The method according to claim 16, wherein a PDA or a computer is user connectable directly to the control means using the communication interface to retrieve and record in real-time information acquired by data acquisition means.
 19. The method according to claim 16, wherein a PDA or a computer is user connectable directly to the control means using the communication interface to display visual feedback relative to user performances.
 20. The method according to claim 16, wherein a PDA or a computer is practitioner connectable directly to the external interface of the user in order to retrieve the parameters previously recorded by the external interface and to analyse the physical performances of the user.
 21. The method according to claim 16, wherein parameters of the control means are practitioner modifiable in real-time using the external interface of the practitioner by the communication interface.
 22. The method according claim 16, wherein a computer is practitioner connectable directly to the control means using the communication interface to retrieve in real-time information acquired by the data acquisition means.
 23. The method according to claim 16, wherein a computer is practitioner connectable directly to the control means using the communication interface, and to perform recording of the movement parameter and to analyze the physical performance of the user.
 24. A computer program comprising a code executing the method described in claim
 16. 